Correct Answer: Black

Solution : According to the dice rule, if two or three positions of the same dice are given with two common faces but in different orientations, then out of those two common faces the faces that are not common are opposite to each other.
In the given dice, two faces with the colours White and Red are common. So, the remaining colours on the faces are Blue and Black. So, Blue and Black colours are the opposite faces of each other in the given dice.

So, the face opposite to the face showing Blue is Black. Hence, the second option is correct.